Control system and valve structure for gas ovens

ABSTRACT

A gas oven system includes a main oven burner and a pilot burner providing an intermittent control pilot flame and a standing pilot flame in response to gas supplied from a manually and thermostatically operated oven control. A safety valve admits gas to the main burner when the control pilot flame is sensed. A pilot flow control valve structure has an inlet receiving standing pilot flow, an inlet receiving heater pilot flow and an outlet providing both standing pilot and heater pilot flows to the pilot. The valve structure includes one valve preventing all flow to the pilot unless the valve is opened manually or is held open by sensed standing pilot flame, and another valve interrupting heater pilot flow whenever the oven door is open.

United States Patent [191 Sekera, Jr.

[ 1 Oct. 23, 1973 Primary Examiner-Edward G. Favors Attorney-Richard D.Mason et al.

ABSTRACT A gas oven system includes a main oven burner and a pilotburner providing an intermittent control pilot flame and a standingpilot flame in response to gas supplied from a manually andthermostatically operated oven control. A safety valve admits gas to themain burner when the control pilot flame is sensed. A pilot flow controlvalve structure has an inlet receiving standing pilot flow, an inletreceiving heater pilot flow and an outlet providing both standing pilotand heater pilot flows to the pilot. The valve structure includes onevalve preventing all flow to the pilot unless the valve is openedmanually or is held open by sensed 9 Claims, 4 Drawing FiguresPATENIEllnct 23 ms SHEET 10F 4 O/OOOOOOOO CONTROL SYSTEM AND VALVESTRUCTURE FOR GAS OVENS The present invention relates to an improvedcontrol system and valve structure for gas ovens, and more particulalyto a system and valve structure for preventing unsafe conditions due toopening of the oven door or absence of a standing pilot flame.

For reasons of safety is it desirable to prevent operation of a gas ovenwhen the oven door is open. For one example, in mobile homes and otherrecreational vehicles gas ovens may be designed to use outside air forcombustion. In this situation, operation of the oven with the door opencan defeat this arrangement and cause dangerous oxygen depletion withinthe vehicle. Moreover, operation of any oven with the door open producesother safety problems such as the dangerof fire.

In many oven installations there is provided a small standing pilotflame for igniting a control pilot flame and/or for igniting the mainoven burner. Itis undesirable to admit gas to the oven when the standingpilot flame does not exist. This problem is of importance in mobilehomes and recreational vehicle installations because the standing pilotgas is normally shut off while the vehicle is in motion and the standingpilot flame must periodically be reestablished.

Important objects of the present invention areto provide an improvedsystem and an improved valve structure for controlling pilot gas flow inanoven so that the oven cannot be operated when the oven door is open orwhen no standing pilot flame is present; to provide an improved pilotcontrol valve structure; and to provide a novel arrangementforcontrollinggas flow to the oven in dependence upon the position of theoven door and in dependence upon the presence or absenceof a standingpilot flame.

Briefly, the above and other objects and advantages of the invention areachieved by the provision of an improved system and valve structure fora gas oven including an oven door movable between closed and openedpositions and a main over burner disposed within the oven. A pilotburner located adjacent the main burner produces a standby pilot flameand a control pilot flame in response to the supplyof a pilot flame gasflow and a control flame gas flow. A safety valve admits gas to the mainburner in response to presence of the control pilot flame. An ovencontrol provides the standing pilot gas flow and the control pilot gasflow by way of a novel pilot valve structure.

In accordance with one feature of the invention, the pilot valvestructure includes a valve serving to interrupt the control pilot gasflow whenever the oven door is moved from its closed position.Consequently, no control pilot flame is present when the oven door isopened, and as a result of operation of the safety valve, no gas isadmitted to the main burner. However, during opening of the oven door,the standby pilot flame continues to exist.

The pilot valve structure includes a single outlet for supplying bothstanding and control pilot gas flows to the dual rate pilot. The valvestructure includes a first inlet for receiving control pilot flow and asecond inlet for receiving standing pilot flow. A first valve memberinterrupts all flow to the dual rate pilot in its normally closedposition and is movable to an open position by manual operation in orderto light the standing pilot flame and thereafter is held inopenpositionby means of a flame sensor disposed adjacentthe standing pilot flame.The door responsivecontrol pilot flow valve is disposed in the housingof thepilot valve structure, and serves to control flowthrough'thecontrol pilot flow inlet in response to position of theovendoor.

The invention together with the above and other objects and advantagesmaybe better understood from the following detailed description of anembodiment of the invention illustrated inthe accompanying drawingwherein:

FIG. 1 is a largely schematic'and diagrammatic simplifled view ofagasoven includinganoven control system and valve structure embodying theprinciples of the present invention;

FIG. 2 is afragmentary partly sectional view of the pilot valvestructure and pilot burner of the system of FIG. 1;

FIG. 3 is a view similar to FIG. 2 illustrating the structure in adifferent condition; and

FIG. 4'is a view similar to FIG. 2 illustrating the structure in yetanother differentcondition.

Having reference now to FIG. l'of the drawing, there is illustrated anoven control system designated as a whole bythe reference numeral lflandconstructed in accordance with the principles of the present inven-'tion. The oven control system 10 is associated with an oven 12,illustrated only in part, and includes a novel pilot-control valvestructure generally designated as l4 constructed in accordance withfeaturesof the present invention. The system 10 and valve structure 14may be incorporated into anydesired type of oven installation, and forpurposes of example the illustrated oven 12 is associated with a freestanding range including a door 16 hingedly mounted upon an oven frontwall 18 for movement between open and closed positions. In accordancewith important features of the invention, the system 10 and valvestructure 14 prevent operation of the oven when the oven door is opened,and prevent admission of gas to the oven when no standing pilot flame ispresent.

In order to heat the interior of the oven 12 there is provided a mainoven burner 20 disposed beneath a flame shield 22 at the bottom of theoven 12 Disposed adjacent the main burner 20 is a pilot burner 24capable of producing a continuing standing pilot flame and anintermittent control pilot flame in response to'the flow of gas into thepilot burner 24 at lesser and greater rates of flow.

Fuel is supplied to the main burner 20 from a gas supply manifold 26 byway of an oven control 28, a conduit 30, a safety valve 32 and aconduit34. Although the oven control system 10 of the present invention may beadapted for many different types of oven installations and may make useof many different types of oven con trols, the control 28 of theillustrated arrangement is of the type disclosed and claimed in U. 8.-Pat. No. 3,563,457 Bergquist et al. This control includes an operatingknob 36 for controlling the operation of the oven 12. I

More specifically, the operating knob 36. of the control 28 may be movedto a pilot off" position wherein no gas flows from the manifold 26 intothe oven control system 10. This position is useful in connection withgas ovens of mobile homes, recreational vehicles and the like whereinall gas is shut off during movement of the vehicle. In order tocondition the oven 12 for use, the

knob 36 is moved from the pilot off to an off" position wherein gas isadmitted through the control 28 only to a standing pilot supply conduit38 and not to other components of the system. As appears more fullybelow, gas flowing through conduit 38 produces a standing pilot flame atthe pilot burner 24 serving as a continuing source of ignition withinthe oven 12.

Operating knob 36 is movable from the of position to a variety ofoperating positions wherein desired oven cooking temperatures arethermostatically maintained. In such positions the oven temperature ismain tained at the temperature selected through setting of the knob 36by the admission of fuel from the manifold 26 through the control 28 toa control pilot supply conduit 40 and to the conduit 30 and safety valve32 as well as to the standing pilot supply conduit 38. Reference may behad to said US. Pat. No. 3,563,457 for a further description of thestructure and operation of the oven control 28 beyond that necessary foran understanding of the present invention.

Admission of fuel from the control 28 and conduit 40 to the pilot 24,under the control of the valve structure 14 as described below, resultsin admission of fuel to the oven burner 20. More specifically, fuelflowing from the valve structure 14 to the pilot 24 through a conduit 42enters through an inlet fitting 44 (FIGS. 2, 3 and 4) to a tubular pilotbody 46 and is mixed with primary air entrained through an aerationaperture 48. The outlet end of tube 46 includes an upper outlet 50 and alower outlet 52, and a deflector 54 is spaced from the end of thetubular body 46.

The standing and control pilot flames produced by pilot 24 areillustrated in FIGS. 3 and 4. When standing pilot fuel flow provided tothe pilot 24 from control 28 through conduit 38, valve structure 14 andconduit 42 is ignited, a standing pilot flame designated by referencenumeral 56 and indicated by broken lines in FIGS. 3 and 4 is produced.This standing pilot flame impinges upon a flame sensing devicecomprising a fluid charged blub 58 communicating by way of a conduit 60with the valve structure 14.

When flow to the pilot 24 is augmented by the control pilot gas flowfrom the control 28, conduit 40, valve structure 14 and conduit 42, theflame at the pilot 24 extends into the deflector 54, and is partlydeflected downward to produce the control pilot flame 62 shown in brokenlines in FIG. 4. Standing pilot flame 56 continues to exist at upperpilot outlet 50 while the control pilot flame is produced at the loweroutlet 52. The control pilot flame impinges upon a flame sensing devicecomprising a fluid charged bulb 64 communicating with safety valve 32 byway of a conduit 66.

Having reference now to the safety valve 32, this type of valve is wellknown to those skilled in the art, and any commercially available valvecould be used in the system 10. One example of such a safety valve maybe found in US. Pat. No. 3,469,781 Sekera, Jr. Valve 32 includes aninlet 68 connected to the control 28 by conduit 30 and an outlet 70communicating with the burner 20 by way of conduit 34. The function ofthe safety valve 32 is to permit the flow of gas into the main burner 20only during such time as a control pilot flame 62 is sensed at the pilotburner 24 by bulb 64. Heating of bulb 64 causes the valve 32 to beoperated from its closed condition to its open condition in response tothe establishment of a control pilot flame 62, and cooling of bulb 64 inthe absence of a control pilot flame 62 results in closing of the valve32. Reference may be had to said US. Pat. No. 3,469,781 for a furtherdescription of the structure and operation of the safety valve 32.

In accordance with important features of the present invention, thepilot control valve structure 14 is provided in the oven control system10 in order to prevent unsafe operation of the oven 12 when no standingpilot flame 56 is present and/or when the oven door 16 is moved from itsclosed to its open position. In general, the valve structure 14 includesa housing 76 closed by a cover plate 78 and having an inlet 80communicating with the standing pilot supply conduit 38, an inlet 82communicating with the control pilot supply conduit 40, and an outlet 84communicating by way of the conduit 42 with the pilot burner 24.

Unsafe operation of the oven when the oven door is open is prevented bymeans of a valve generally designated as 86 incorporated in the valvestructure 14. The valve 86 is controlled by a door responsive operatinglinkage 88 to open communication between the control pilot supplyconduit 40 and the pilot 24 only when the oven door 16 is in its closedposition, and to prevent the flow of gas to the pilot 24 when the ovendoor 16 is in its open position.

Undesirable admission of fuel to the oven 12 when no standing pilotflame 56 has been established is prevented by means of a valve generallydesignated as 90 controlling flow through the outlet 84 of the valvestructure 14 to the pilot 24. Valve 90 is normally closed and can bemoved to its open position by means of a manual operating linkage 92,and can be maintained in its open position by a standing pilot flameresponsive operating linkage 94.

Referring more specifically now to the valve structure l4, the twovalves generally designated as 86 and 90 are of similar construction.Each includes a movable valve member including a reciprocating sliderelement 96 movable in a bore in the housing wall and provided withgrooves 98 for flow of gas through the valve when in its open position.A washer 100 is press fitted onto each slider element 96 to retain anO-ring seal 102 in position between the washer 100 and the housing.Normally a spring 104 held in compression between the washer 100 and aspring retainer and fitting element 106 forces the O-ring seal 102 intosealing relation between the washer 100 and the housing 76 in order tomaintain the respective valve 86 or 90 in its normally closed position.Each slider element 96 is provided with an operating pin 108 extendinginto the interior of the housing 76 for moving the slider element 96against force of the spring 104 in order to open the respective valve 86or 90.

In accordance with a feature of the invention, the valve 86 permits gasto flow to the pilot 24 to produce the control pilot flame 62 only whenthe oven door 16 is moved to its closed position. When oven door 16 isopen, the valve 86 is in its closed position as illustrated in FIG. 2 ofthe drawings and no fuel flows from the conduit 40 to the pilot 24through the valve 86. As a result, no control pilot flame 62 isestablished and the valve 32 does not open to admit fuel to the ovenburner 20.

In order to operate the valve 86 between positions, the cover plate 78of the valve structure 14 carries a boss 110 slidably supporting a pushpin 112 carrying a push plate 114. A spring 116 held in compression be-'tween the boss 110 and the plate 114 holds the pin 112 in its normalposition illustrated in FIG. 2 when the oven door is open. When the ovendoor is closed, the door responsive operating linkage 88 (FIG. 1) whichmay include any suitable force transmitting structure indicated bybroken lines 117 coupled between adoor guide 118 and a push rod 120 orother pushing device engages the push plate 1 14 and forces the push pin1 12 into the housing 76 by overcoming the force of the spring 116. Theend of the pin 112 engages and depresses the operating pin 108 of theslider element 96 thus opening the valve 86 and permitting fuel to flowfrom the inlet 82 through the housing 76 and from the outlet 80 throughthe conduit 42 to the pilot 24.

In accordance with another feature of the invention, the structure 14includes the valve 90 for preventing the admission of any fuel to theoven 12 until such time as a standing pilot flame 56 is established.When no standing pilot flame is present, the valve 90 is in its normallyclosed position as illustrated in FIG. 2 of the drawing. In order tocondition the oven for operation, a standing pilot flame 56 isestablished. In order to permit gas to flow to the pilot 24 in order toignite a standing flame, the operator of the oven first operates themanual linkage 92 in order to open the valve 90. With reference to FIG.1, it can be seen that in the illustrated arrangement the manual linkage92 includes a push button 122 movable within a housing 124 supported inthe front wall 18 of the oven. When the push button is depressedagain sttheforce of a push button spring 126 a suitable force transmittingarrangement designated by a broken line l28 moves a push rod 130 inorder to open the valve 90.

The valve 90 is manually controlled in response to movement of the pushrod 130 by means of a push pin 132 (FIGS. 2-4) reciprocally supported bya boss 134 in the cover plate 78 and normally held in the positionillustrated in FIG. 2 by means of a spring 136 held in compressionbetween the boss 134 and a push plate 138. When the push rod 130 movesagainst the push.

plate 138, the pin 132 moves into housing 76 to depress the operatingpin 108 of the slider element 96 thereby to open the valve 90.

Once the valve 90 has been opened by operation of the manual linkage 92and fuel is flowing to the pilot 24, the standing pilot flame 56 isignited by a match or other suitable ignition means. When the standingpilot flame 56 is established as illustrated in FIG 3 of the drawings,the flame heats the standing pilot flame sensing bulb 58 causingexpansion of the fluid held therein. This expansion is accommodated byan expansible diaphragm 140 disposed within the housing 76 andcommunicating with the bulb 58 through conduit 60. Expansion ofdiaphragm 14 causes a power element 142 to pivot an operating lever 144of the flame responsive operating linkage 96 around a pivot member 146.The lever depresses the operating pin 108 of the valve 90 to hold thevalve 90 open so long as the standing pilot flame 56 continues.

The operation of the oven control system and of the pilot control valvestructure 14 will be apparent to those skilled in the art in view of thepreceding detailed description. Briefly, the structure 14 is shown inFIGS. 1 and 2 in a non-operating or fully shut down condition whereinthe oven door 16 is open and wherein no flame exists at the pilot 24. Inthis condition, the valves 86 and 90 of the valve structure 14 are bothclosed and no gas is admitted to the pilot burner 24. In addition, thevalve 32 is closed in the absence ofa control pilot flame 62 and no gasis admitted to the main oven burner 20.

In order to prepare the oven 12 for operation, the operating knob 36 ofthe oven control 28 is moved from the pilot off to the off position sothat communication is established to the standing pilot flow conduit 38leading to the inlet of the valve structure 14. The push button 122 isdepressed and to open the valve and establish communication between theconduit 38 and the conduit 42 and pilot 24. The gas flowing from thepilot 24 is ignited and, as illustrated in FIG. 3, the standing pilotflame is produced. The standing pilot flame 56 heats the bulb 58 and thediaphragm expands and lever 144 holds the valve 90 in its open position.At this time the push button 122 may be released by the operator of theoven 12 and the valve 90 will nevertheless be maintained in its openposition by the continuing standing pilot flame 56.

The standing pilot flame 56 continues to burn to maintain a continuingsource of ignition in the oven 12. In order to carryout a cookingoperation with the oven 12, the oven door 16 is closed. When thisoccurs, the valve 86 is opened to permit the flow of fuel from thecontrol pilot flow conduit 40 through the valve structure 14 and conduit42 to the pilot 24. When the operating knob 36 of the control 28 ismoved to an operating position, gas flows through conduits 40 and 42 tothe pilot burner 24, and as illustrated in FIG. 4 a control pilot flame62 is established. Simultaneously, the control 28 admits gas to theconduit 30 and inlet 68 of the valve 32. When the control pilot flame 62heats the bulb 64, the valve 32 is operated to its open condition andfuel flows through the valve 32 and conduit 34 to the main burner 20where it is ignited by flame at the pilot burner 24.

If at any time during operation of the oven the oven door 16 is movedfrom its closed position, flame at the main burner 20 is discontinuedand the control pilot flame 62 at the pilot burner 24 is alsodiscontinued while the standing flame is permitted to continue forreignition when the door is closed. More specifically, when the door 16is open, the door responsive operating linkage 88 causes the valve 86 toclose to prevent flow from the control pilot flow conduit 40 through theinlet 82 into the valve structure 14. As a result the control pilotflame 62 is discontinued and the bulb 64 cools. The safety valve 32 thencloses to discontinue flow into the main burner 20 until such time asthe oven door 16 is reclosed.

While the present invention has. been described with reference todetails of the illustrated embodiment, it should be understood that suchdetails, do not limit the invention as defined in the following claims.

What is claimed and desired to be secured by Letters Patent of theUnited States is:

1. A pilot control system for a gas oven includingan oven door movablebetween closed and open positions,

a main burner, a pilot burner, a flame responsive safetyvalve forsupplying gas to the main burner in response to a predetermined controlpilot flame, and an oven control operable to control the supply of acontinuing standing pilot gas flow and operable to control the flow ofan intermittent control pilot gas flow, said pilot control systemcomprising:

a standing pilot flame sensor for sensing the presence of a standingpilot flame at said pilot burner;

a control pilot flame sensor coupled to the safety valve for sensing thepresence of a control pilot flame at said pilot burner;

first normally closed valve means coupled between the oven control andthe dual rate pilot for interrupting the standing pilot flow and thecontrol pilot flow to the dual rate pilot;

manually operated means for opening said first valve means;

means coupled between said standing pilot flame sensor and said firstvalve means for holding said first valve means open in response to asensed standing pilot flame;

second normally closed valve means coupled between said oven control andsaid pilot burner for interrupting only the control pilot flow to thedual rate pilot; and

means coupled between the oven door and said second valve means foropening said second valve means in response to closing of the oven door.

2. The system of claim 1, further comprising a housing having a firstinlet receiving the standing pilot gas flow from the oven control, asecond inlet receiving the control pilot gas flow from the oven control,and an outlet communicating with the pilot bumer,'said first and secondvalve means being supported by said hous- 3. The system of claim 2, saidfirst valve means controlling flow through said outlet.

4. The system of claim 3, said second valve means controlling flowthrough said second inlet.

5. A pilot control apparatus for an oven having a door, a pilot burnerproducing standing pilot and control pilot flames when supplied withstanding pilot and control pilot gas flows, a main burner, and a safteyvalve for supplying gas to the main burner in response to control pilotflame, said pilot control apparatus comprising in combination:

a housing having an outlet adapted to be connected to the pilot burner,a first inlet adapted to receive the standing pilot gas flow, and asecond inlet adapted to receive the control pilot gas flow;

a first valve in said housing controlling flow through said outlet;

a second valve in said housing controlling flow through said secondinlet;

first valve operating means including a flame sensor adapted to bedisposed adjacent the pilot burner for opening said first valve means inresponse to the presence of flame at the pilot burner and for closingsaid first valve means in response to the absence of flame at the pilotburner;

second valve operating means including a manually operable member foropening said first valve while said member is-manually operated; and

third valve operating means adapted to be coupled to the oven door foropening said second valve when the door is closed and closing saidsecond valve when the door is open.

6. The apparatus of claim 5, each said valve including a valve seatmeans, a valve member movable relative to said valve seat means into andout of sealing relation with the valve seat means, the resilient meansurging the valve member into sealing relation with the valve seat means.

7. The apparatus of claim 6, said first valve operating means includingan expansible diaphragm communicating with said flame sensor and mountedwithin said housing, and means coupled between said diaphragm and saidvalve member of said first valve for controlling the position of saidfirst valve in response to movement of said diaphragm.

8. The apparatus of claim 7, said second valve operating meanscomprising a push button, and force transmitting means coupled betweensaid push button and said valve member of said first valve for openingsaid first valve in response to pressing of said push button.

9. A control system for a gas oven of the type including a main burner,control pilot means and an oven door movable between closed and openpositions, said system comprising in combination:

a safety valve connected between a supply of gas and the main burner;

flame sensing means disposed in flame sensing relation with the controlpilot means and coupled to said burner valve for opening said burnervalve in response to a predetermined control pilot flame condition;

a control pilot supply conduit coupled between a source of gas and thecontrol pilot means;

a control pilot valve in said control pilot supply conduit;

and valve operating means coupled between the oven door and said controlpilot valve for closing said control pilot valve in response to openingof the oven door.

1. A pilot control system for a gas oven including an oven door movablebetween closed and open positions, a main burner, a pilot burner, aflame responsive safety valve for supplying gas to the main burner inresponse to a predetermined control pilot flame, and an oven controloperable to control the supply of a continuing standing pilot gas flowand operable to control the flow of an intermittent control pilot gasflow, said pilot control system comprising: a standing pilot flamesensor for sensing the presence of a standing pilot flame at said pilotburner; a control pilot flame sensor coupled to the safety valve forsensing the presence of a control pilot flame at said pilot burner;first normally closed valve means coupled between the oven control andthe dual rate pilot for interrupting the standing pilot flow and thecontrol pilot flow to the dual rate pilot; manually operated means foropening said first valve means; means coupled between said standingpilot flame sensor and said first valve means for holding said firstvalve means open in response to a sensed standing pilot flame; secondnormally closed valve means coupled between said oven control and saidpilot burner for interrupting only the control pilot flow to the dualrate pilot; and means coupled between the oven door and said secondvalve means for opening said second valve means in response to closingof the oven door.
 2. The system of claim 1, further comprising a housinghaving a first inlet receiving the standing pilot gas flow from the ovencontrol, a second inlet receiving the control pilot gas flow from theoven control, and an outlet communicating with the pilot burner, saidfirst and second valve means being supported by said housing.
 3. Thesystem of claim 2, said first valve means controlling flow through saidoutlet.
 4. The system of claim 3, said second valve means controllingflow through said second inlet.
 5. A pilot control apparatus for an ovenhaving a door, a pilot burner producing standing pilot and control pilotflames when supplied with standing pilot and control pilot gas flows, amain burner, and a saftey valve for supplying gas to the main burner inresponse to control pilot flame, said pilot control apparatus comprisingin combination: a housing having an outlet adapted to be connected tothe pilot burner, a first inlet adapted to receive the standing pilotgas flow, and a second inlet adapted to receive the control pilot gasflow; a first valve in said Housing controlling flow through saidoutlet; a second valve in said housing controlling flow through saidsecond inlet; first valve operating means including a flame sensoradapted to be disposed adjacent the pilot burner for opening said firstvalve means in response to the presence of flame at the pilot burner andfor closing said first valve means in response to the absence of flameat the pilot burner; second valve operating means including a manuallyoperable member for opening said first valve while said member ismanually operated; and third valve operating means adapted to be coupledto the oven door for opening said second valve when the door is closedand closing said second valve when the door is open.
 6. The apparatus ofclaim 5, each said valve including a valve seat means, a valve membermovable relative to said valve seat means into and out of sealingrelation with the valve seat means, the resilient means urging the valvemember into sealing relation with the valve seat means.
 7. The apparatusof claim 6, said first valve operating means including an expansiblediaphragm communicating with said flame sensor and mounted within saidhousing, and means coupled between said diaphragm and said valve memberof said first valve for controlling the position of said first valve inresponse to movement of said diaphragm.
 8. The apparatus of claim 7,said second valve operating means comprising a push button, and forcetransmitting means coupled between said push button and said valvemember of said first valve for opening said first valve in response topressing of said push button.
 9. A control system for a gas oven of thetype including a main burner, control pilot means and an oven doormovable between closed and open positions, said system comprising incombination: a safety valve connected between a supply of gas and themain burner; flame sensing means disposed in flame sensing relation withthe control pilot means and coupled to said burner valve for openingsaid burner valve in response to a predetermined control pilot flamecondition; a control pilot supply conduit coupled between a source ofgas and the control pilot means; a control pilot valve in said controlpilot supply conduit; and valve operating means coupled between the ovendoor and said control pilot valve for closing said control pilot valvein response to opening of the oven door.